Arsenal head coach Mikel Arteta recorded the first victory of his reign with a 2-0 success against Manchester United.
The Gunners took the lead on eight minutes when Sead Kolasinac's cross found Nicolas Pepe, who swept the ball past David De Gea.
Pepe also hit the post before Sokratis doubled their lead three minutes before the break, smashing home after De Gea's parry from a corner.
United had more possession in the second half with substitute Andreas Pereira hitting the side-netting and Marcus Rashford firing narrowly over.
But the Gunners held firm for their first home league win since October and climb up to 10th place on 27 points. Man Utd remain fifth with 31 points.
Arsenal: 11 Jan v Crystal Palace (A)
Man Utd: 11 Jan v Norwich (H)